Gestational diabetes screening in subsequent pregnancies of previously healthy patients

OBJECTIVE: Our purpose was to evaluate women without gestational diabetes mellitus in an index pregnancy for the likelihood that gestational diabetes would develop and for risk factors for carbohydrate intolerance in a subsequent pregnancy.Study Design: A retrospective review of medical records at a teaching hospital universally screening for gestational diabetes identified multiparous women who had been delivered twice between 1994 and 1997 and who, in the first (index) pregnancy, had had a normal result on a screening test with 50 g of glucose used in a "glucola" beverage (< or =140 mg/dL). RESULTS: In this population with normal glucose screening values in the index pregnancy, 352 (92.4%) of 381 women had at least one risk factor for gestational diabetes. However, none of the 381 women had gestational diabetes in the subsequent pregnancy (0/381, 95% confidence interval < or =1%), including 45 (12. 4%) who had an abnormal result on the 50-g glucose screening test. Regression analysis showed this test result in the index pregnancy (P =.001) to be the only studied variable significantly associated with the 50-g glucose value in the subsequent pregnancy. CONCLUSION: Despite a high rate of risk factors for gestational diabetes, women in our population with a normal glucose value in an index pregnancy have a minimal risk (<1%) that gestational diabetes will develop in a subsequent singleton pregnancy within 4 years. This factor may be included in determining whether women should undergo screening for gestational diabetes.     

Recurrence of gestational diabetes mellitus.

OBJECTIVE: To assess the influence of several maternal and neonatal variables on the recurrence of gestational diabetes mellitus. METHODS: A retrospective review was conducted on 90 of our patients whose index pregnancy was complicated by gestational diabetes mellitus and whose subsequent pregnancy was also managed at our institution. RESULTS: Forty-seven women (52%) had a recurrence of gestational diabetes mellitus in their subsequent pregnancy. These 47 women had an increased body mass index (BMI) (32.8 +/- 8.2 versus 28.9 +/- 7.2 kg/m2; P < .03) and more large for gestational age (LGA) neonates (38 versus 14%; P < .05) and more of them required insulin during their index pregnancy (38 versus 19%; P < .05) than did those who did not have a recurrence of gestational diabetes mellitus. Women who developed a recurrence of gestational diabetes mellitus also had higher fasting (P < .05), 1-hour, 2-hour, and total glucose tolerance test values (P < or = .01) during their index pregnancy. CONCLUSION: Women with a history of gestational diabetes mellitus who have a BMI greater than 35 kg/m2, whose previous newborn was LGA, and who required insulin during their previous pregnancy are at increased risk for recurrence of gestational diabetes mellitus.     

The Long-Term Follow-up of Women with Gestational Diabetes

Four hundred and forty-seven women who had gestational diabetes have been retested at intervals from 1 to 12 years following diagnosis; 49 (11%) were found to be diabetic and 35 (7.8%) had impaired glucose tolerance using the WHO criteria. An abnormal glucose tolerance test in the puerperium and obesity at the time of retesting had significant associations with abnormal glucose tolerance at follow-up. However, the best predictive factor of the likelihood of the development of significant hyperglycaemia was the recurrence of gestational diabetes in a subsequent pregnancy, since 28% of these women were diabetic and a further 4% had impaired glucose tolerance at the time of follow-up. These findings indicate that the criteria used for the diagnosis of gestational diabetes at the Mercy Maternity Hospital, Melbourne (1-hour greater than or equal to 9 mmol/l together with a 2-hour greater than or equal to 7 mmol/l) are appropriate for an Australian population.     

Gestational diabetes mellitus: does it recur in subsequent pregnancy?

The recurrence of glucose intolerance was examined in 36 women with an index pregnancy complicated by gestational diabetes who received antepartum care at the same institution because of a subsequent pregnancy. Standard oral or intravenous glucose tolerance tests were used to document glucose intolerance or gestational diabetes. Twenty patients had gestational diabetes in the subsequent pregnancy, whereas one third of the patients tested did not demonstrate an abnormality of carbohydrate metabolism. The patients with consecutive pregnancies complicated by gestational diabetes were heavier and were delivered of heavier neonates than the patients who did not develop gestational diabetes again. Unlike the nondiabetic group, the patients who remained gestationally diabetic weighed significantly more in the subsequent pregnancy than in the index pregnancy. These results indicate that patients with gestational diabetes should be tested in subsequent pregnancies because of the impact of gestational diabetes on birth weight. However, these results also suggest that the glucose tolerance test may not be a reliable test for the detection of abnormal carbohydrate metabolism.     

Diabetes mellitus following gestational diabetes: role of subsequent pregnancy

Objective  This study was designed to determine the rate of diabetes up to 13 years after pregnancies complicated by gestational diabetes and to identify risk factors for developing diabetes. The role of a subsequent pregnancy, with and without gestational diabetes, was also examined.
Design  This was a retrospective cohort study of women with gestational diabetes.
Population and setting  Women who had gestational diabetes in their first pregnancy between 1989 and 2002 were identified through a population-based perinatal database in Nova Scotia, Canada.
Methods  Subsequent diagnoses of diabetes, up to 13 years after the first pregnancy, were obtained from physician billing and hospital discharge databases. Cox proportional hazards regression models were used to estimate adjusted relative risks (RR) and 95% confidence intervals.
Main outcome measures  Diagnosis of diabetes after pregnancy.
Results  Of the 1401 nulliparous women with gestational diabetes, 251 women (17.9%) developed diabetes in the follow-up period. The cumulative incidence at 1, 5, and 10 years was 5.9, 14.8, and 22.2%, respectively. Factors significantly associated with an increased risk of developing diabetes mellitus included a pre-pregnancy weight of ≥86 kg (RR = 1.8, 95% CI 1.2–2.9), insulin therapy during the index pregnancy (RR = 4.1, 95% CI 2.1–7.9), neonatal hypoglycaemia (RR = 2.6, 95% CI 1.6–4.2), and a subsequent pregnancy with gestational diabetes (RR = 2.3, 95% CI 1.6–3.4).
Conclusion  Indicators of the severity of gestational diabetes, defined by insulin use, neonatal hypoglycaemia, and recurrent gestational diabetes in a subsequent pregnancy, are important in predicting a subsequent diagnosis of diabetes. Our findings do not support the theory that subsequent pregnancy, per se , increases the risk of developing diabetes.     

Recurrence of gestational diabetes.

The recurrence rate of gestational diabetes in 58 patients who had had the foregoing pregnancy complicated by diabetes was estimated to be 30% if our former criteria for abnormal glucose tolerance were strictly applied and 25% if our new, more stringent criteria were used. The recurrence rate is not influenced by prophylactic administration of pyridoxine. The perinatal morbidity complicating the 'second' pregnancy of former gestational diabetics was not increased in those patients who were not treated again, as compared with those who were. Recurrent gestational diabetes is associated with a degree of overdiagnosis in an attempt to detect all gestational diabetics. It is suggested that recurrent gestational diabetes occurs mainly in prediabetic patients.     

Screening for gestational diabetes mellitus in the subsequent pregnancy: is it worthwhile?

OBJECTIVE: The purpose of this study was to determine, among women without evidence of gestational diabetes mellitus during their first pregnancy, the likelihood of, and associated risk factors for, the development of gestational diabetes mellitus in the subsequent pregnancy. STUDY DESIGN: This was a retrospective cohort study, with a time frame of 1991 to 1999. RESULTS: Of 3710 women without gestational diabetes mellitus in the first pregnancy, 1% (37 women) were subsequently diagnosed with gestational diabetes mellitus in the second pregnancy. These 37 women, when compared (by means) to women without gestational diabetes mellitus in their second pregnancy, were more likely to be older (age 21 years vs 19 years) and obese (first visit body mass index, 28 kg/m(2) vs 25 kg/m(2)) and to have an interpregnancy weight gain of >5 kg (93% vs 49%) and a longer mean interpregnancy interval (33 months vs 24 months). Regression analysis revealed that, during the first pregnancy, a first visit body mass index of >29 kg/m(2) (odds ratio, 2.2; 95% CI, 1.1-4.5) and a serum glucose screen of >101 mg/dL (odds ratio, 8.3; 95% CI, 2.5-27.9) were associated significantly with the development of gestational diabetes mellitus in the second pregnancy, as was an interpregnancy weight gain of >5 kg (odds ratio, 10.8; 95% CI, 2.5-46.3). All women who subsequently had gestational diabetes mellitus had at least one of these risk factors. CONCLUSION: Among women without gestational diabetes mellitus in the first pregnancy, the risk of gestational diabetes mellitus in a second pregnancy is low. Therefore, screening all such women in the second pregnancy may not be justified.     

Gestational diabetes diagnosed in third trimester pregnancy and pregnancy outcome.

BACKGROUND: The clinical significance of gestational diabetes diagnosed in the third trimester is unclear. A prospective observational study was performed on a cohort of women without pre-existing gestational diabetes or other medical disorders to examine the effect of gestational diabetes on pregnancy complications and infant outcome. METHODS: Four hundred and eighty-nine consecutive women were assessed at 28-30 weeks by random glucose screening and/or a 75 g oral glucose tolerance test. The subsequent management was according to established departmental protocols. The outcome of pregnancy was compared among the groups with negative screening, positive screening but normal glucose tolerance, and gestational diabetes which was controlled with diet therapy. RESULTS: Women with gestational diabetes (n=67 or 13.7%) had significantly increased maternal age, pre-pregnancy weight and body mass index, hemoglobin levels at booking and at 36-38 weeks, and incidences of parity >1, pre-eclampsia, and female infants, while the gestational age was shorter and there was no significant difference in the birthweight outcome or neonatal morbidity. CONCLUSIONS: Despite diet treatment, gestational diabetes diagnosed in the last trimester is associated with increased risk of pre-eclampsia and shorter length of gestation, and this is likely to reflect a pathological process rather than the physiological effect of pregnancy on maternal glucose tolerance.     

Clinical predictors for a high risk for the development of diabetes mellitus in the early puerperium in women with recent gestational diabetes mellitus

OBJECTIVE: The purpose of this study was to identify which maternal, antepartum, or neonatal clinical parameters were predictive for a high risk of diabetes mellitus in the puerperium in women with recent gestational diabetes mellitus and to calculate the associated diabetes mellitus rates and odds ratios. STUDY DESIGN: One thousand six hundred thirty-six women underwent an oral glucose tolerance test within 1 to 4 months of delivery. Demographic, historic, and antenatal glycemic parameters and neonatal outcome parameters were tested by univariate and multivariate logistic regression for risk of postpartum diabetes mellitus. Continuous variables were divided into quartiles that compared the upper to lower quartile adjusted odds ratio and prevalence of diabetes mellitus. RESULTS: Postpartum diabetes mellitus was diagnosed in 230 women (14.1%) according to the American Diabetes Association criteria (1997). No maternal demographic or neonatal parameters were significantly associated with diabetes mellitus. The final model of independent predictors in decreasing significance included the highest fasting plasma glucose level during pregnancy, any fasting plasma glucose level of > or = 105 mg/dL (class A(2)), the area under the curve of pregnancy oral glucose tolerance test, gestational age at diagnosis, previous gestational diabetes mellitus history, and 50-g glucose challenge test results. The fasting plasma glucose level was the best discriminator, with a 21-fold (95% CI, 4.6-96.3) increased odds ratio comparing the 4th quartile (fasting plasma glucose level, >121 mg/dL; diabetes mellitus rate, 36.7%) to 1st quartile (fasting plasma glucose level, < 95 mg/dL; diabetes mellitus rate, 0.5%). The presence of previous gestational diabetes mellitus or current class A(2) gestational diabetes mellitus approximately doubled the odds ratio for diabetes mellitus. The odds ratio increased 3- to 4-fold when the area under the curve was > or = 33.36 min small middle dot g/dL (4th quartile) or the glucose challenge test was > or = 155 mg/dL (2nd-4th quartiles) and decreased > 50% if gestational diabetes mellitus was diagnosed at > 27 weeks (3rd-4th quartile). CONCLUSION: During pregnancy, the highest fasting glucose level, followed by the severity of glucose intolerance, and earlier gestational diabetes mellitus diagnosis were the best predictors for postpartum diabetes mellitus. Diabetic education should begin during pregnancy, especially for women who are identified to be at a high risk when they are highly motivated and under medical care.     

Correlation between one-hour, 50-g glucose screening values in successive pregnancies

OBJECTIVE: To investigate the relationship between one-hour, 50-g oral glucose screening test results in successive pregnancies and to assess the risk of gestational diabetes in women who had a previously negative glucose screening test during a prior pregnancy. STUDY DESIGN: Sixty-nine women were studied who had successive pregnancies delivered at intervals ranging from one to four years. All had glucose screening tests performed at 24-32 weeks of gestation during both pregnancies. The relationship between glucose screening test results was examined for interpregnancy intervals of up to two, three and four years. RESULTS: The correlation for interpregnancy glucose screening test results was .60, .49 and .47 for pregnancy intervals of up to two, three and four years, respectively (P < .001). The mean glucose screening test result was 108 +/- 23 mg/dL for prior pregnancies and 104 +/- 21 mg/dL for subsequent pregnancies (no significant difference). A screening test result > or = 140 mg/dL occurred in 1.6% of cases in which a previous test result was < 140 mg/dL during a prior pregnancy. CONCLUSION: A glucose screening test result of < 140 mg/dL during pregnancy is strongly predictive of a subsequent negative screening test result in a succeeding pregnancy when it occurs within four years. Under such circumstances, the risk of gestational diabetes during a subsequent pregnancy is reduced by 85-95% to no more than 0.3%.     

Oral glucose tolerance testing at gestational weeks < or =16 could predict or exclude subsequent gestational diabetes mellitus during the current pregnancy in high risk group

BACKGROUND: An oral glucose tolerance test with a result that is negative but close to the diagnostic cut-off in early pregnancy was hypothesized to serve as a predictor of subsequent gestational diabetes in a high risk group. The aim of the study was to determine those cut-off values of OGTT at gestational weeks < or =16, which can predict or exclude subsequent onset of GDM in a high risk group. METHODS: Pregnant women at high risk of gestational diabetes (n = 163) underwent a 2-h, 75-g oral glucose tolerance test at gestational weeks < or =16 were analyzed in this study. In the event of a negative result, subsequent oral glucose tolerance tests were performed at gestational weeks 24-28 and 32-34. The sensitivity, the specificity, the positive and negative predictive values and the Odds ratio of the best cut-off values of fasting and postload glucose levels were calculated. RESULTS: The best cut-off values to exclude subsequent GDM for fasting and postload glucose were 5.0 and 6.2 mmol/l, respectively. In combination, the best cut-off values were 5.3 mmol/l for fasting and 6.8 mmol/l for postload glucose, with negative predictive values of 0.97 and 0.71 and sensitivities of 96.9 and 86.3 at gestational weeks 24-28 and 32-34, respectively. Combination of these cut-off values with obesity proved to be very predictive for gestational diabetes by gestational weeks 32-34, with an Odds ratio of 6.0 [95% confidence interval: 1.7-21.0]. CONCLUSIONS: With regard to the very high negative predictive value of the method, pregnant women with glucose levels of < or =5.3 mmol/l at fasting and of < or = 6.8 mmol/l at postload in gestational weeks < or =16 should undergo subsequent oral glucose tolerance testing merely at gestational weeks 32-34. Approximately a quarter (24.5%) of the pregnant women at risk of gestational diabetes satisfied these criteria.     

Perinatal complications in women with gestational diabetes mellitus

BACKGROUND: The aim of the study was to examine the outcome of the pregnancy and neonatal period in 1) women with gestational diabetes mellitus and non-diabetic pregnant women, and 2) in women with early and late diagnosis of gestational diabetes mellitus. METHODS: Included were 327 women with gestational diabetes mellitus and 295 non-diabetic women, who were screened with a 75 g oral glucose tolerance test because of risk factors for gestational diabetes. Women with gestational diabetes mellitus were treated with low-caloric diet and insulin when appropriate, while women in the control group received routine antenatal care. RESULTS: Gestational age at delivery was significantly lower in the group with gestational diabetes mellitus, both when considering all deliveries (39.1+/-1.7 weeks versus 39.8+/-2.0 weeks, p<0.05) and only those with spontaneous onset of labor (38.8+/-2.0 weeks versus 40.0+/-1.6 weeks, p<0.05). The frequency of macrosomia was increased, although not statistically significant (8% vs. 2%, p=0.07), and the rate of admission to the neonatal ward was significantly increased (18% vs. 9%, p<0.05) in the group with gestational diabetes. Women with early diagnosis of gestational diabetes mellitus had a significantly increased need for insulin treatment during pregnancy (36% vs. 9% p<0.05) and a significantly higher occurrence of diabetes mellitus at follow-up from two months until three years postpartum. CONCLUSIONS: This study of women with gestational diabetes mellitus and non-diabetic pregnant women showed that gestational diabetes mellitus was associated with a significantly lower gestational age at delivery and an increased rate of admission to the neonatal ward. Women diagnosed with GDM before 20 weeks of gestation had an increased need for insulin treatment during pregnancy and a high risk of subsequent overt DM, compared with women diagnosed with GDM later in pregnancy.     

Disorders of glucose tolerance among women with pregnancy induced hypertension

OBJECTIVES: Gestational diabetes is observed to coexist with pregnancy induced hypertension. Insulin resistance might be associated with both of these diseases. DESIGN: To assess the association between glucose intolerance and subsequent development of hypertension in pregnancy. MATERIAL AND METHODS: Glucose levels at the time of routine screening for gestational diabetes among 79 women with pregnancy induced hypertension and 79 normotensive women have been compared. RESULTS: Hypertensive women were statistically more often obese, their pregravid BMIs were greater and their pregnancy weight gain was higher. Among hypertensive women gestational diabetes has been more often diagnosed. As compared with normotensive, women developing PIH had significantly higher glucose levels after 50 g and 75 g of glucose load. CONCLUSIONS: Women with pregnancy induced hypertension are at increased risk of gestational diabetes. Even within the normal range, levels of plasma glucose levels were higher among hypertensive women.     

Predictive factors of developing diabetes mellitus in women with gestational diabetes

BACKGROUND: To investigate which factors during gestational diabetes pregnancies correlate with the risk of developing impaired glucose tolerance or diabetes 1 year postpartum and to compare this risk in women with gestational diabetes and women with a normal oral glucose tolerance test during pregnancy. METHODS: Of 315 women with gestational diabetes, defined as a 2-hr blood glucose value of at least 9.0 mmol/l at a 75-g oral glucose tolerance test, who delivered in Lund 1991-99, 229 (73%) performed a new test 1 year postpartum. We compared maternal and fetal factors during pregnancy with the test value at follow up. A control group of 153 women with a 2-hr test value below 7.8 mmol/l during pregnancy were invited to a new test 1 year postpartum and 60 (39%) accepted. RESULTS: At 1 year follow up, 31% of the women with gestational diabetes but only one of the 60 controls showed pathologic glucose tolerance and one had developed diabetes. The following factors in women with gestational diabetes were identified as predicting impaired glucose tolerance or diabetes at 1 year follow up: maternal age over 40 and--in a multiple regression analysis, independent of each other--a high 2-hr value at oral glucose tolerance test during pregnancy and insulin treatment during pregnancy. CONCLUSION: The risk of developing manifest diabetes after gestational diabetes may be high enough to justify a general screening or diagnostic procedure in all pregnant women to identify women with gestational diabetes and a postpartum follow up program for them. This study did not identify any particular factor during pregnancy with enough precision to predict a later progression to diabetes.     

Maternal low birth weight and gestational hyperglycemia

We aimed to investigate whether birth weight could predict the subsequent risk of gestational diabetes and impaired glucose tolerance. Consecutive women with a singleton pregnancy and gestational diabetes (n = 50) ,impaired glucose tolerance (n = 50) and normoglycemia (n = 200) were included in the study. Birth data were collected from original hospital records of the women. Women with gestational hyperglycemia were significantly older and heavier than those with normoglycemia. Maternal birth weights significantly declined for each class of glucose tolerance (3389 ± 644; 3184 ± 583 and 3077 ± 661 ,respectively for women with normoglycemia ,impaired glucose tolerance and gestational diabetes). After adjustment for age ,gestational age and weight gain ,maternal diabetes ,and pre-pregnancy body mass index ,maternal birth weight was negatively related to impaired glucose tolerance (OR 0.88 ,95% CI 0.81-0.97) and to gestational diabetes (OR 0.82 ,95% CI 0.74-0.91) in a multiple logistic regression model. These findings suggest that women with low birth weight constitute a group at increased risk for both gestational impaired glucose tolerance and diabetes.     

妊娠期血糖异常产后母儿随访分析

目的　探讨妊娠期不同程度的血糖异常者产后发生糖尿病 (DM )的高危因素和预防措施 ,以及妊娠期血糖异常对其子女的远期不良影响等。方法　对 1994～ 2 0 0 0年 196例妊娠期血糖异常者进行产后随访 ,其中50 g葡萄糖筛查阳性 (50g阳性 ) 12 3例 ,葡萄糖耐量减低 (IGT) 3 7例 ,妊娠期糖尿病 (GDM ) 3 6例。此 3组人群均进行 75g葡萄糖耐量试验 (OGTT )及血脂检测。对其子女行血糖检测及生长发育水平观察 ,包括测量头围、胸围、身高及体重等。结果　 196例随访者中发生IGT、空腹血糖异常 (IFG)、DM共 2 2例 (占 11 2 2 % ) ,其中 50g阳性、IGT、GDM者其产后平均 3年内血糖异常发生率依次为 2 43 %、2 1 62 %、3 0 56% ,后两者与 50 g阳性相比差异有显著性意义 (P <0 0 1) ,其相关因素与产妇高龄 (40 90 % )、肥胖体型 (2 1 2 7% )、孕期血糖控制不良(45 45% )、产后体重显著增加 (40 91% )有关。 14 5例随访子女中虽血糖检测未见异常 ,但发生肥胖者 16例 (占11 0 3 % ) ,且其母孕期血糖控制不良者 9例 (占 56 2 5% )。结论　GDM及IGT者产后DM发生率高 ,应引起重视。妊娠期及时有效地控制高血糖及产后继续饮食调理与加强运动疗法 ,对维护产后母儿健康有益     

Remote prognosis of primiparous women with preeclampsia

OBJECTIVE: To describe the maternal characteristics of pregnancy and perinatal outcome of primiparous women with preeclampsia, to determine the recurrence rate and to define the maternal risk factors for preeclampsia in subsequent pregnancies. METHODS: A retrospective cohort study. Two groups of patients were defined: the study group consisted of 380 primiparous women with preeclampsia, and in a control group of 385 primiparous women without preeclampsia. The patients were followed during their consecutive deliveries. Multiple logistic regression analysis was used to determine the independent risk factors for the recurrence of preeclampsia in the second pregnancy. RESULTS: In the study and the control group there were a total of 1207 and 1293 deliveries, respectively. Of the 380 primiparous women in study group, 305 (80%) were identified as suffering from mild preeclampsia, 64 (17%) from severe preeclampsia, 10 (2.6%) from super imposed preeclampsia and only one (0.3%) had eclampsia. Primiparous with severe preeclampsia had a significantly higher rate of preterm delivery then those with mild preeclampsia (34 versus 11% respectively, P<0.0001). In addition, the study group had significantly higher rate of perinatal mortality (3.4 versus 0.3%, P=0.013) and perinatal complications. The recurrence rate of preeclampsia was significantly higher in the study group (25% versus 1.9%, P<0.0001). When adjusted for confounding variables, gestational diabetes was strongly associated with the recurrence of preeclampsia in the second pregnancy (OR 3.72 95% CI 1.45-9.53). CONCLUSION: Primiparous women with preeclampsia are at an increased risk for recurrence in subsequent pregnancies. Gestational diabetes in primiparous women with preeclampsia is an independent risk factor for developing preeclampsia in the second pregnancy.     

Gestational diabetes. Is a 50-g screening result > or = 200 mg/dL diagnostic?

OBJECTIVE: To evaluate the diagnosis of gestational diabetes based on a 50-g, one-hour glucose screening test result > or = 200 mg/dL. STUDY DESIGN: Retrospective ascertainment of pregnant women who had a 50-g, one-hour glucose screening test result > or = 200 mg/dL was performed among prenatal care registrants. The diagnosis of gestational diabetes was determined by 100-g, three-hour oral glucose tolerance test (GTT) results and/or repeated fasting serum glucose measures. RESULTS: In 1995, 69 women were referred to the gestational diabetes clinic with a 50-g result > or = 200 mg/dL. Four women could not be classified, two had pregestational glucose intolerance and four charts were unavailable. Of the remaining 59 women, 11 (19%) had normal three-hour GTTs, and 48 (81%) were diagnosed with gestational diabetes (35 [59%], A1; 13 [22%], A2). There was one large-for-gestational-age (LGA) infant born in the nondiabetic group (9%), 13 LGA infants born in the A1 group (37%) and 6 LGA infants born to the A2 diabetics (46%). The relationship between maternal diagnosis and LGA outcome was statistically significant. CONCLUSION: A 50-g screening test result > or = 200 mg/dL is not diagnostic of gestational diabetes. Nearly one of five such women had a normal three-hour oral GTT. Overdiagnosis of gestational diabetes may lead to unnecessary pregnancy surveillance and intervention.     

Effects of new criteria for type 2 diabetes on the rate of postpartum glucose intolerance in women with gestational diabetes.

OBJECTIVE: Our purpose was to determine the impact of the 1997 American Diabetes Association diagnostic criteria for type 2 diabetes mellitus on the rate of postpartum glucose intolerance in women with gestational diabetes. STUDY DESIGN: Women identified as having gestational diabetes were instructed to undergo a 75-g, 2-hour glucose tolerance test 4 to 6 weeks after delivery. The results were retrospectively categorized with both the 1979 National Diabetes Data Group criteria and those recommended by the American Diabetes Association in 1997. RESULTS: Though the rate of overt diabetes mellitus did not increase when the 1997 American Diabetes Association criteria were used (7.8% vs 5.6%, P = not significant), the rate of impaired glucose metabolism was higher (20.1% vs 5%, P <.001). Most women (28/30, 93%) with a nondiagnostic glucose tolerance test result by the older criteria had abnormal results by the newer criteria. Fifty women had abnormalities of glucose metabolism under 1997 American Diabetes Association criteria; 34% of these women had fasting plasma glucose values in the normal range. Of the 25 women with impaired glucose tolerance, 16 (64%) had only an abnormal 2-hour value, with normal fasting glucose values. CONCLUSIONS: The rate of postpartum abnormalities in glucose metabolism more than doubles when the 1997 American Diabetes Association criteria are applied; more women are identified with lesser degrees of impairment. However, relying on fasting glucose levels alone, without glucose tolerance testing, may miss one third of women with such abnormalities.     

Postpartum metabolism and autoantibody markers in women with gestational diabetes mellitus diagnosed in early pregnancy

OBJECTIVE: Our purpose was to study postpartum metabolism and autoantibody markers of type 1 diabetes mellitus in women with gestational diabetes mellitus diagnosed in early pregnancy. STUDY DESIGN: Thirty women with gestational diabetes diagnosed in early pregnancy were compared with 72 women who had gestational diabetes diagnosed in late pregnancy. Glucose tolerance, parameters of carbohydrate and lipid metabolism, and antibodies to glutamic acid decarboxylase and to islet cells were measured. RESULTS: The percentages of overt diabetes and abnormal glucose tolerance were significantly higher in the early-pregnancy group (26.7% vs 1.4%; P =.0002; and 40% vs 5.56%; P <.0001; respectively). Only 1 woman had positive test results for antibodies to the islet cells. The rate of positive test results for antibodies to glutamic acid decarboxylase was similar in both groups (13.7% vs 9.3%). CONCLUSIONS: Women with early gestational diabetes have an increased risk of postpartum diabetes mellitus, whereas those with late-onset gestational diabetes have a minimal risk. In women predisposed to type 1 diabetes, gestational diabetes develops either early or late in pregnancy.